RRB Group D GK Questions 2026

The Third Anglo-Maratha War of 1817 to 1818 was settled by a set of separate treaties with the Maratha houses, and the one with the Holkar chief of Indore was signed at Mandsaur, or Mandeshwar, in January 1818.

The National Bureau of Soil Survey and Land Use Planning, an institute of the Indian Council of Agricultural Research, works from Nagpur and prepares the soil maps and land capability surveys on which district planning rests.

Running water cuts gullies in the soft alluvium of the Chambal basin, and where those gullies deepen and spread over a wide tract the land becomes a maze of steep channels and ridges unfit for cultivation, which geographers call badland and local people call the ravines or beehad.

Gypsum, that is calcium sulphate, supplies calcium that replaces the sodium held on the soil particles, and once the sodium is set free it can be washed out of the field by irrigation and drainage, restoring structure to land that had become hard and impermeable.

Laterite soil forms on hill slopes of Karnataka, Kerala, Tamil Nadu, Odisha and Assam under heavy rain and high temperature, and after manuring it carries these plantation crops well; cashew in particular does well on the laterite of the Kerala and Karnataka coast.

Bhangar is the older alluvium of the northern plains, lying above the flood level on slightly raised terraces, coarser in texture and marked by nodules of calcium carbonate known as kankar, which lower its fertility and hinder the movement of water.

Black soil, called regur, formed from the lava of the Deccan trap and is so closely tied to this one crop that it is popularly called black cotton soil.

Fertility needs mineral nutrients such as nitrogen, phosphorus and potassium from the weathered rock, and organic matter, that is humus from decayed plants and animals, which holds water, feeds soil organisms and releases nutrients slowly.

Weathering is the natural breaking down of rock by temperature, water, wind and living things, and it is the process that makes soil in the first place; it is not a technique that a farmer applies to save soil, so it cannot be a conservation method.

In sheet erosion water spreads over a wide slope and carries away a thin, even film of topsoil, so nothing obvious is left behind to see, and the loss is noticed only years later as falling yields.

What it is rich in is calcium carbonate, magnesium, potash and lime, and remembering that short list is the safest way to answer any statement question on this soil.

A delta is built out of silt that a river carries down and drops where it meets the sea, so deltaic land is alluvial by definition, and the eastern coastal deltas of the Mahanadi, Godavari, Krishna and Kaveri are among the most fertile rice tracts of the country.

It is a molecule of sixty carbon atoms arranged in a closed cage of pentagons and hexagons, exactly like the panels of a football, and it is named after the architect who designed domes of the same geometry.

Ethanoic acid, better known as acetic acid and familiar as vinegar in dilute form, has the formula CH3COOH, and the -COOH group at the end is what makes it acidic, since it releases a hydrogen ion in water and turns blue litmus red.

Vegetable oils contain unsaturated chains with carbon to carbon double bonds; hydrogen adds across those double bonds in the presence of nickel or palladium, turning them into single bonds, so the oil becomes saturated and sets into a solid fat.

Going from methane to ethane, or from ethanol to propanol, adds one carbon atom of mass twelve and two hydrogen atoms of mass one each, which is fourteen in all, and it is this fixed step that defines a homologous series.

In graphite every carbon atom is bonded to only three others within a layer, so the fourth valence electron of each atom is free to move along the layer, and moving electrons constitute an electric current.

Catenation is the self-linking of atoms of the same element, and carbon shows it more strongly than any other element because the carbon to carbon bond is short and exceptionally strong, which is why chains of many carbon atoms remain stable.

When enough air reaches the burner, every carbon atom of the fuel is oxidised fully to carbon dioxide and the flame is blue and hot, giving the maximum heat for the gas consumed.

An alkyne contains a carbon to carbon triple bond, which needs at least two carbon atoms, so the series begins with ethyne, C2H2, also called acetylene and used with oxygen in welding.